Projector for page printers



July2,1946. w. H. mm 2,403,270

' PROJECTOR FOR PAGE PRINTERS Original Filed July 17, 1940 2Sheets-Sheet l INVENTOR I4 23 II WILLIAM H. EDDY vw a 1946. H; E Y2,403,270

PROJECTOR FOR PAGE PRINTERS Original Filed July 17, 1940 2 Sheets-Sheet2 FIG. 4 I23 48 I24 71/! l x v n9 '0: V k D IZI 4 2 70,2

H3 7 H5 I I29 I we ll! n2 11 I47 5 g I NVENTOR WILLIAM H. EDDY A ORNEYPatented July 2, 1946 UNITED STATES PATENT 'GFFICE PROJECTOR FOR PAGEPRINTERS William H. Eddy, Downers Grove, Ill., asslgnor to TeletypeCorporation, Chicago, Ill.,

ration of Delaware Original application July 11, 1940, Serial No.

346,002. Divided and this application September 18, 1941, Serial No.411,374

14 Claims. 1

The present invention relates to printing telegraph apparatus and moreparticularly to page printers for use in projection systems.

This application is a division of application Serial No. 346,002, filedJuly 17, 1940. l

' 'a page printer, of the type shown in U. S. Patent No. 1,904,164,designed to give upon a screen a running account of received messagematter, through the instrumentality of an optical system comprising anarrangement of inclined mirrors so'that the printer and lamp'housing maybe located at the lower part of a suitable cabinet, and the screenformed as a part of the upper forward wall of the cabinet and positionedabove the printer compartment.

Specifically, the page printer isv mounted on rails supported in astructural frame to which is pivotally mounted the lamp housing, in suchmanner that the lamp housing with its condensing lenses is positionableso as to embrace within the field of projection the last line ofprinting, and also to include eight or ten printed lines. Printing iseffected on a Cellophane strip and the image of the record producedthereon is projected through the optical system onto the screen. TheCellophane web or strip is drawn upwardly 1 through the projectionfield. The characters on the section of the web in theprojection fieldare so arranged as toform horizontal lines one above the other, and theimages ofsaid horizontal lines of characters areprojected on th screen.The

horizontal lines 'of images on the screen move upwardly across thescreen similar to the movement of the web through the projection field.

The foregoing and other objects and features of the invention willappear from the following detailed description taken in conjunctionaccompanying drawings, in which, I I

Fig. -1 is a cross-sectional view of the printerprojector according tothe present invention;

with the Fig. 5 is a perspective view of the printer impact equalizingmechanism according to the present invention; and

Fig. Sis an enlarged side view ofa type bar head.

Having reference to the drawings in which like reference charactersindicate similar parts throughout the several views, the combinationpage printing and projecting apparatus according, to the presentinvention is housedlin a cabinet, indicated generally by the numeral H,which is provided in the lower portion thereof with a door (not shown),and in the upper portion with a translucent projector screen l3. Securedto the floor of cabinet H are two angle iron rails l4 (only one of whichis shown in Fig. 1) which provide atrack for the frame l5 which supportsthe page printing apparatus, indicated generally by the numeral IS, thelamp housing l1, and the optical arrangement represented generally bycondensing lenses l8, small mirror I 9 and ob jective lens 2|. Wheels 22are journaled to the bottom side members of the frame t5 and c0-.operate in rolling relation with rails l4,-whlch are provided withindentations 23 into which the.

wheels 22 are admitted when the frame l5,.in assuming its fully insertedposition in the cabinet ll, rests upon spacing bosses 25. In the fullyinserted position, the framel5 is anchored I by means of bolts 30 to thebase of the cabinet ll. With this arrangement, the frame is easilyinsertable in the cabinet H by means of rollers 22, andmoreoveris'adapted, when the proper position has been assumed, to restupon spacers 25 and to be anchored to the cabinet by bolts.

At each side of frame l5 and disposed at the rear thereof are pivotsupports 24 for a frame 28 which carries the lamp housing I! andcondenser lenses I 8. A bar 20 (Fig. 4) is pivoted to frame 26, and thelower end of said bar is provided with a hook portion (not shown)which,'when the frame 26 is swung upwardly about pivots 24 to Fig. 2 isa cross-sectional view of the printer showing a printing impactequalizing mechanism;

Fig. 3 is an enlarged cross-sectional p nter platen and platen frame;

Fig'. 4 is an enlarged side View and partial se'ction of theprintermechanism and associated view of the lamp housing and part of theoptical arrangement;

facilitate removal of ,the printer for servicing, is held inits upwardposition by the engagement of said hooked portion with a stud,. inwell-known manner, thebai- 20 tius serving as'abrace or support. Thelamp housing I! comprises an outer casing 21 (Fig. 1) which is securedtoa plate .28 fastened to a crossbar 29 of the frame 28.

Contained within the lamp housing l1 .and suitably spaced from theouter. casing '21 thereof is abaflle plate 3| which rests upon thebottom 01' the housing I! and extendsupwardly toa point closetothet'op,as illustrated in Fig. 1. The bot tom of the housing I! is provided,-between the outer casing 21 and the baflle plate 9|,with apertures' 92.This construction permits the flow of is a baifle plate 99 (Fig. l) ofsubstantially the same area asthe opening 99. Lamp 91 is ad- Justablyclamped to a bracket 99, which in turn is adjustably supported by thefloor of the bouting II. -A reflector 9| is spring clamped by a carrier92 which is adjustably supported, through the instrumentality of a rod99 and the enlarged mounting holes for plates 95, by the outer casing 21of the lamp housing I].

In the embodiment of the invention shown in thedrawings, a condensinglens system I9, comprising two piano-convex lenses and oneconvexo-convex lens, is provided, these lenses being suitably clamped byclamps 99 to plates 29, 99, and 91 which are appropriately separated byspacing posts (not shown). Plate 91 is secured along its top edge to acrossbar 99 '(Fig. 1) of frame 29. Plates 29, 99.- and 91 are suitablyaper-. tured to provide a field of projection of such area as to presentupon the screen I9 a predetermined number of lines of printing producedon the record strip or web 99 of transparent material.

As previously mentioned, the optical systemof the present inventionincludes a mirror I9 and an objective lens 2|. The optical system alsoincludes a mirror 5| supported in the upper part of the cabinet I I, andthrough this system the image is projected upon the screen I9. The

, convection currents. between. the outer casing 21 The web 99 is thendirected over a roller 9| to which is fixed a ratchet wheel92, theratchet wheel and roller being carried on a shaft 99 Journaled in theplates 99 secured to side frames '19 and I9. Co-operating 'with theroller 9| is a pressure roller 99 which is carried, on a standard 99secured to a rock shaft 91. Pressure roller 99 is drawn into pressingrelation with roller 9| by means of a spring 99. Secured to rock shaft91 and located in juxtaposition to plate 99 is a pressure roller releaselever 99. Co-operating with pressure roller 9| and maintaining thiscondition until lever 99 is again released from the shoulder I9| topermit spring 99 to bring roller 99 again into pressing relation withroller 9|. Associated with the ratchet wheel 92 is a pawl member I92(Fig. 1) which is pivoted to a bell mirror I9 is adjustably pivoted on apair of 7 2| facilitate the proper positionment of the image on thescreen.

- Having reference to Fig. 1 a page printer of the type'shown in U. S.Patent No. 1,904,199-is mounted in'the frame I9. The printer, indicatedgenerally as I9, has been modified in certain respects to adapt it foruse with the projector of the present invention. prises the side framesI9 and. 1.9 (Fig. 4) to which is pivoted at 9| a platenframe indicatedgenerally as 92. The usual cylindrical form of-platen has been dispensedwith. in the present embodiment of the invention and has beensubstituted by the disc'form of platen I19 shown in Figs. 3 and 4, andwhich will be hereinafter described.

- To provide a running account of the message.

printed on the page material, a delivery mech is" provided whichcomprises a means for permitting the record material to escape from thepply roll, suitable guides, and a web pulling means whereby the pagematerial is advanced "through the printing zone. 7 99 in being withdrawnfrom the roll 99 is directed over-a slackbar which is pivoted at 99 andis norm'allybiased clockwise by a spring 99 tomaintain the pagematerialflor Cellophane'web' taut between the roll 99 and a flangedcylindrical guide 91 carried on ashaft 99. iournaled in 99 dependingfromside frames 'I9 and .19.

The page material I The page printer comcrank lever I99 carried on apivot shaft I99. The depending arm of bell crank I99 is pivoted to oneend of a push rod I99, the other end of which .is shouldered. toco-operate with a function ball I I99 in the manner shown in theaforementioned Patent No. 1,904,164. Thus, in response to apredetermined selection a function lever. similar to function lever I9'Ishown in Fig. 4 1's selected to raise the free end of push bar I99upwardly into the path of the function bail blade I99. Then,

when the push .rod I99 is actuated leftwardly by the function bail I99,clockwise rotation is imported to hell crank lever I99 to impart inturn,

downward movement to pawl I92. In-this manner, the ratchet-wheel 92 isrotated clockwise one step. which, through the oo-operation of pressurerollers 9I- and 99, acts in oil-operation with a web pulling device todeliver? a predetermined amount of record material 99 from the supplyroll 99 to the printing zone and the projection area.

The record material 99 is'brought to the printing position by means of apulling or drawing mechanism now to be described; The record material 99as it leaves roller 9| is directed around guide rods I99, III, and H2.These guide rods may take the form of a fixed rod carrying guide rollersthereon to eliminate friction. From the guide rod 2 the record material99 is di-,

rected vertically through the printing zone and projection areato aguide rod 9 carried by a U-shaped shifting frame member "9 (Figs. 1 and4) pivotally carried on pivots H9 and H9 suitably iournaled in-the frameII; The page material 99 is then directed around a guide rod III carriedin supports 9 (Fig.4) depending. from bars II9 secured to angleiron-cross bars |2I and I22 of frame I9. From thence. the p e materialis directed around a spindle I29 nxed to a shaft I29 iournaled instandards I29 supp0rted on said b'ars'lll.

Shaft m is interconnected through a friction clutch .(not shown) to apulley I29. Continuous counterclockwise rotation (as viewed in Fig. 4)is imparted to pulley I29 through the instrumen- 'tality of a beltconnected to a pulley in .fixed to the main operating shaft I92 of thepage printing apparatus shown in PatentNo'. 1,994.- 194. Shaft I92carries a sear-I99 which meshes with a pinion gear I99 fixed to shaftI99 of a moto'r I99 (Fig. 1). Motor I99, therefore, through gears I99and I99, shaft; I92. pulleylfl, and belt Ramparts continuous rotation topulley.,..|29.'

which, through the friction clutch m, imparts a constant torque throughshaft I 24 tothe spindle I23. With thisarrangement the page materialtaut condition between the r 49 is maintained in a spindle I23 and theroller 5i. Thus; when the ratchet 921s rotated one step a predeterminedamount of the, page material 45 is delivered from the supply roller 83,which material is immediately taken up by the spindle I23 to preservethe taut condition of the page material.

As disclosed in the aforementioned Patent No. 1,904,164, the pageprinter I6 is controlled telegraphically by a selector magnet I31. Thisis connected in a signal line (not shown) on which are impressed codecombinations of signalling impulses. The code signals control, through aselector magnet I31 of asword and T-type selector (not here shown, butillustrated and described in said patent), a series of selector vanesI38 which, in turn, controls through bell cranks (shown in said patent),a set of curved code bars I (Fig. 4). Code bars I41 and said bell cranksare supported on a movable type carriage, indicated generally bythehumeral I42, which is Type carriage I42 is also providedtwith a,spacing rack I 52 which co-operates with' a spacing mechanism (notshown) similar to that illustrated in Patent No. 1,904,164, to'controlthe movement of type carriage I42 to form character spaces, tending inthis movement to wind up a carriage return spring mechanism (not shown).Upon receipt of the carriage return signal, a function lever (similar tolever I01) is selected and the carriage return mechanism is actuated inthe manner described in the aforementioned Patent No. 1,904,164. Thecarriage return mechanism is thereupon permitted, due to the energystored therein, to return the type carriage I42 to its'normal orbeginning-of-line position. I

A pull bar bail I53 is mounted in the type carriage I42 and is ried onthe bottom side thereof on a stud I55. Roller I54 operates between apair of blades J55 and I51 of a main printing bail I55 so, that ball I53can be reciprocated by bail I58 in any character spacing position of thetype carriage I42. Fastened 'to-the printing bail I55 is one end of aprinting spring I5 9, the other end of which is connected to a printingblow adjustment means as shown in Patent No. 1,904,164. -Bail I58 ismounted on a shaft I5I on whichis also carried a printing bail actuatorI 52 which co-operates with a printing cam I53. Actuator I52 carries atthe end of its upper arm a stud I54 whichhas abutting relation only withprinting bail I58 and Is not permanently connected thereto, which-is topermit spring printing. Printing bail I55 is'also provided with a pairof arms I55 which carry a function lever bail I50. Also carried on.shaft I5I is a function bail comprisingarms I55, I58, and m. Arm 10s isprovided with a follower roller which co-operates with a function bailcam I58, and arm I51 supports on its end the function bail alade I08.

Associated'with the selectorfvanes I38 are a olurality of functionlevers I01 mounted on pivot rod in and provided withindividual springsI13 provided with a roller I54 carwhich tend. to rotate the functionlevers clockwise into registry with the selector-vanes I38; The functionlevers I01 are normally-held out of engagement with the selector vanesI38 by means of the rod I55 ofthe function lever bail- As previouslymentioned, the. platen frame 82 pivotally supported on pivots, in sideframes 18 and 10. The, platen comprises a. circular. disc I13 rotatablymounted, on 'acarriage I14 which is slidable on rodsI1-5 and I15 carriedby platen frame 82. Platen carriage I14 is connected to the typecarriage, as will be presently described,

so as to be movable therewith, the effective printing edge of the platenI13 being locatedcoincident with the printing point or zone determinedby the path of operation'of the type bar I45.

The platen frame 82 is adapted to be rocked from the letters or unshiftposition to the "figures" or shift position in the manner fully setforth in the aforementioned Patent No. 1,904,164.

Briefly, the side frame of the platen frame 82(as shown in Fig. 4) isprovided with a lug I11 which operates between two adjustable stop I18and I19. Adjacent to lug I11 there is pivoted to the side frame of theplaten frame 82 on pivot I81,

the upper end of a link I82, the lower end of which is pivoted to thehorizontal arm of a bell crank lever I83 pivotally mounted at I84. Tothe lower end of the depending arm of bell crank I83 is pivoted a pushbar I 85, thei'ree'e'nd of which overlies=a rearwardly directed arm ofthe function lever I01. Push bar I85 is also provided with a shoulderI85 which co-operates with the function lever bail blade I08. The platenframe 85'and platen I13 are shown in the "letters or unshi'ft position,with the stop lug I11 against the upper stop screw I15. This conditionis achieved when the function ball blade I 08 has operated upon theshoulder I85 to move the push bar I 85 leftwardly to rotate the bellcrank I83 clockwise, thus raising the link I52 to cause the platen frame82 to rock clockwise.

A correspondingly similar construction is .pro-

' vlded for the figures or shift mechanism.

That is, a shift function lever similar to lever I01, is provided which,when selected, is caused to rotate clockwise to bring its rearwardlyextending arm into operation to raise apush bar; similar to bar I85,into the path of the function bail blade I08 which, when it is permittedto operate leftwardly (as viewed in Fig. 4), will cause abell crank,similar to bell crank l83,,to pull down a link similar to link I52 torock the platen frame 82 counterclockwise to bring its stop I11 againstthe" lower stop screw- I15. The platen frame 82 is maintained in itsshift or unshift position by a spring actuated detent member I81 actingon a detent roller I85.

In Fig. 3 is'illustrated the manner in which the platen carriage I14 isconnected to the type carriage I42 so as to be movable therewith. Aspreviously mentioned,v the I platen carriage I14 is slidably supportedon rods I15 and I15. Carriage I14 is provided with an eccentric stud Ien- Saged by the forked end or extremity of a. bar I85, the other end ofwhich is secured to a member Isl which is secured by screws I52 to. thetype carriage I42. As more fully described in the parent application,the circular platen I13 is rotatably mounted on the platencarriage I14by I meansof an eccentric means I93. By meansof the adjustment I53, theplaten I13 is adjustable toward and away from the record material tovary the clearance therebetween. "A compensatin: adjustment is alsovprovided for the platen 113, i

An important feature of the present invention is the provision of a.platen' so positioned as to reduce to a minimum the obstruction of theprojected image by the platen. To achieve this result the platen I13 istilted with respect to the record material printed upon, sufficiently toclear thelight cone. The peripheral surface of the platen I19, uponwhich printing is effected, is slightly beveled so that in one of theshift positions of the platen the peripheral surface of the platen willbe parallel to the record material. In the present embodiment theperipheralsu-rface of the platen I19 is parallel to the record stripwhen the platen frame "has been shifted to the upper case position, asindicated inFig. 3, by the dotted line I94 of the platen I13.

for a printing operation, the ribbon will be raised to printingpositiondue to the counterclockwise movement imparted to the 1ever292 by thebail I59. When the platen frame 92 is in the position shown in Fig. 3,which is the lower case printgng position, the shield I95, uponoscillation of ever 292, will not be raised sufficiently to beinterposed between the type face I91 and the platen I19. However, whenthe platen frame 92 is in the upper case printing position with theplaten I19 in printing relation with the upper case. type face I99, theshield I95 will, upon reciprocation, be raised so as to becomeinterposed between the lower case type face I91 and the record material,thus preventing any ink which has accumulated on the type face I91 fromsmudging the To compensate for thi arrangement of the platen I19, thetype faces on the type bar I49 are arranged as shown in Fig. 6.Moreover, this arrangement of type faces in cooperation with a shieldI95 (Fig. 9) serves (as will presently appear) to prevent smudgingduring the printing operation. As is well known, the type bar I49 isprovided with an upper case type face I95 and a lower case type faceI91. However, according to the present embodiment the lower case typeface I91 is provided with a slope corresponding to the slope of theperiphery of the platen I13 when in the lower case position. Thedimension 291 of the upper case type I95 is arranged to be slightly lessthan the minimum height 2! of'the lower case type I91. When printing. iseffected in-the lower case position, the type face I95 being lower thanthe type face I91, will not touch the record material and hence nosmudging of the printed record will occur.

' When printing is effected in the upper case position, means isprovidedfor preventing the lower case type face'I91 from coming into directcontact with the surface of the record material. To achieve this resulta shield I95 is provided which-is adapted to be interposed between thetype face 191 and the platen I13 when printing is being effected in theupper case position.

Shield I95 is secured to the ribbon oscillating' member I99, which asdescribedin the aforemen tioned Patent'No. 1,904,164, oscillates theinking v ribbon into and out of the path of the type faces during theprinting operation. The'ribbon oscillator I99 is pivotally articulatedto' arm 29I of a lever 202 which, in turn, is pivoted at 299 to a lever294 pivoted at 229 to the type carriage I42. Lever 294 is arranged tocarry a roller 295 which rides on the bottom side of a rail 205 mountedon the platen frame 92, as disclosed in the aforementioned Patent No,1,904,164. Roller 295 is pressed against the rail 295 by a spring (notshown), so that when the platen frame 92 is rocked between the shift andunshift positions, roller 205 will constantly contact with said rail295, and lever 292 will be'reciprocated therewith. I

The depending arm 299 of the lever 292 is operably associated with thepull bar bail I59 (Fig. 1) so that the reciprocative motion of bail I59will cause the oscillation of the lever 292 about pivot 299, whether theplaten frame 92 is in the shift or the unshift position. Thus, when thebail I59 is in its normal position (the leftward position as shown inFig. 4),,the lever 202 will hold the inking ribbon, through theinstrumentality of the ribbon guide (not shown) located at the upperextremity of member I99 (Fig. 3), in its down:

record material.

Normally, in. making a printed record the impact of the type facesagainst the platen in the lower caseposition is slightly greater than itis in the upper case position of type faces I99, due to the fact thatthe lower case type faces I91 are closer to the type bar pivot I5I thanare the upper case type faces I95. In an ordinary printed record theslight difference in density of printing in each case is notdiscernible. However, due to the characteristics of the transparent webupon which printing is effected for projection, this difference ofdensity of printing is more noticeable. To compensate for this variationin density of printing, the present invention provides means forequalizing the printing impact of the lower and upper case type facesautomatically, so that printing of equal density is produced upon therecord material. The variation in density of printing is more noticeablewhen printing is effected upon transparent record material, such as isused in printer-projector apparatus of the type to which the presentinvention is applied.

Having reference to Figs. 2 and 5, a lever 245 is pivoted at 245 to aplate 241 which is adjustably mounted by means of sIot-and-screwadjusting means to bracket 248 carried by printer frame 19. A spring 249extends between the upper end of lever 245 and a spring post 25I carriedon printing bail I59. The lower end of lever 245 is provided with alaterally extending 'portion 252 which co-operates with a dependingprojection 259 on the upper case shift push bar 254. Lower case andupper case push bars I95 and 254, respectively, are articulated to aplaten shift I Push bar. 254 is maintained in operative relation withcontrol lever 255 by a spring 251 extending from projection 259 on bar254 to a projection 259 on lever 255. Similarly, push rod I95 ismaintained in operative relation with control lever 255 by a spring 259extending from projection 25I on bar I95 to projection 252 on lever 255.

To print a character, the code signal corresponding thereto is receivedby the selector magnet I91 (Fig. 4) which, in turn, controls, throughselector vanes I99 and the aforementioned bell crank levers, the settingof code bars I. They selector cam drum associated with selector ma .net'I91 controls (as described in Patent No.

1,904,164) the initiation of rotation of operatin shaft I92 whichcarries the printing cam I59 and the function cam I99. In proper timedrelation with the setting of code bars I, the printing bail I13 toeffect printing.

The power for effecting the printing operation is supplied by theprinting spring I59 and, as previously mentioned, a means is providedfor automatically varying the power supplied by said spring'inaccordance with the case shift condition of the printer. It has beenfound upon ma nification of the printed record incident to projectionupon a screen, that the difference in the distances of the upperand,lower type faces from the type bar pivot causes a difference in theweight of printing which indicates a difference in the printing impactof said type faces. To equalizethe printing impact so that it issubstantially the same in both upper and lower case, the spring 249 isprovided, which in the-lower case position is caused to resist themovement of the printing spring I 59, thereby reducing the impact of thelower case type face against the platen sufficient- 1y to equal thecorresponding impact of the upper case type face. r

Upon receipt of thelowercase or letters shift signal, the "letters shiftfunction lever II" is selected and operated in the manner described inPatent No. 1,904,164 to raise push bar I85 to bring shoulder I88 thereoninto the path of function lever bail blade I88 which, when operated,urges the range of equivalency are to be embraced within the scope ofthe appended claims. What is claimed is:

1. In a printing apparatus, a printing bail, movable printing meansslidably articulated to said printing bail, power means for operatingsaid printing bail, and other power means rendered operativeautomatically as an incident of a pre determined function of theapparatus for alter- 1 ing the effectiveness of said first mentionedpower means.

2. In a printing apparatus, a printing bail, movable printing meansslidably articulated to said printing bail, case shift-mechanism, powermeans for operating said printing bail, and means operativeautomatically undercontrol of said case shift mechanism for altering theeffectiveness of said power means.

3. In aprinting apparatus, a printing bail,

movable printing means slidably'articulated to" said printing bail, caseshift mechanism, spring means for operating said printing bail, andfurther spring means operative under control of said case shiftmechanism for altering the effectiveness of said firstmentioned springmeans.

4, In a printing apparatus, a printing bail,

. movable printing means slidably articulated to push bar I85 leftwardly(as viewed in Fig. 5) to impart clockwise rotation to controllever 255.Le-

ver 255. besides effecting the shift of the platen frame 82 to theletters case position (as indicated in Figs. 2 and 4), causes the pushbar, 254

.tobe moved rightwardly, and in so doing, the

projection 253 thereon engages the lateral portion 252 of lever 245,thereby imparting counterclockwise movement to lever 245 to stretch thespring 249, thus increasing the tension therein.-

Now, when the printing bail I58 is operated in response to subsequentcharacter code signals, the pull of the printing spring I59 will beresisted by the pull of spring 249, thereby reducing the force of theprinting blow, so that the -impact of printing is equal in both upperand lower case.

When the upper case or figures shift signal is received, the figuresshift function lever I88 is selected and operated to bring shoulder 288of push bar 254 into the path of function lever bail blade I88, which,when operated, urges push bar 254 leftwardly to impart counterclockwiserotation to lever 255, which movement will cause,

' through bell crank lever I88 and link I82, the

tive, since lever 245 and spring 249 are now free to move with printingbail I58, .and no resistance is oflered by spring 249 to the printingspring I59. A spring 2640! very light tension extending from lever 245to spring post 285 on bracket 248 is provided to take up the play of themechanism Although a specific'embodimen't of the invention has beenshown herein, it will be understood that the invention is capable ofmodification, and it is intended that all forms which come within saidprintingbail, case shift mechanism, spring means for operating saidprinting bail, and further spring means operative automatically undercontrol of said case shift mechanism for altering the effectivenessof'said first mentioned spring means.

5. In a printing apparatus, a printing bail,

printing means articulated-to said printing bail, case shift mechanism,spring means for operating said printing bail, and further spring meansoperative under control of said'case shift mechani-sm for altering theeffectiveness of said firstmentioned spring means.

6. In a printing .apparatus, a ball, movable recording means slidablyarticulated to said bail,

. said means comprisingtwo groups of recording I upon aweb, power meansfor operating said means, and spring restraining means operativeautomatically under the control of said first mentioned means foraltering the effectiveness of said spring means.

8. In a recorder, a plurality of type bars, a platen, means responsiveto certain selective operations of said recorder to effect relative easeshifting movement between said type bars and said platen, power meansfor operating said means, spring means for controlling the coactionbetween said type barsand said platen to produce a printed record on aweb, and spring restraining meansresponsive to said selective oper- 7 0ations for altering the effectiveness of said spring means.

work, a type carriage movable with respect to said stationary framework,a printing bail in said stationary frame work, slidableconnecting a 11means between said carriage and said ball to effect recordingoperations, spring loaded opera ating means for said printing bail andspring restraining means operative automatically as an incident of apredetermined function of said recorder for'altering the effectivenessof said operatlng means.

10. In a printing apparatus, a printing bail, printing means articulatedto said printing bail; power means for operating said printing bail,

' selective means effective to apply a predetermined restraint upon saidpower means, and further selective means efiective to release saidrestraint.

I and said platen, power means for operating said means, spring meanseffective to apply apredetermined restraint upon said power means, andmeans efiective to release said restraint.

12. In aprinting apparatus, a platen, printing means co-operable withsaid platen, spring loaded operating means to cause said printing meansto impart a predetermined impact upon said I 12 platen, and springrestraining means connected to said operating means and operableselectively to alter the effectiveness of said operating means.

13. In a printing apparatus, selectively controlled means, printingmeans controlled by said selectively controlled means, case shiftmechanism also controlled by said selectively controlled means, andspring means variably operated by said case shift mechanism in responseto prede- 7 termined operations of said case shift mechanism to alterthe efiectiveness of said printing means.

14. In a printing apparatus, a printing bail,

printing means articulated to said printing bail,

- said selective elements, the control of said spring by said pivotedelement is varied ,to alter the 1 effectiveness of said printing means.

